This description relates to semiconductor devices, and, more particularly, to transient voltage suppressors (TVS) and methods of forming them using wide-band gap materials.
At least some known bidirectional punch-through TVS structures are not symmetrical in terms of electrical performance. In certain devices, such as TVS devices formed of SiC semiconductor material where the etched sidewalls have defects, which are a path for leakage current. Such defects are a risk as they may cause one of the junctions to break down at a different voltage than the other junction, making the performance asymmetrical.
Moreover, control of the integrated charge in each semiconductor layer provides greater control over the ability of the device to operate at particular circuit conditions. Epitaxy provides good control in many cases, however, especially for low voltage operation, epitaxial layers do not provide sufficient control of integrated charge.